Liquid fuel burning apparatus



2,2Xgo,858

Nov. 5, 1940.

J. A. wlLsoN ETAL LIQUID FUEL BURNING APPARATUS Fild Aug. 30. 1938 3Sheets-Sheet 1 Nov. 5, 1940. J. A. wlLsoN Erm.

LIQUID FUEL BURNING APPARATUS- Filed Aug. 30, 1958 3 Sheets-Sheet 2 WM YNov. 5, 1940. J. A. wlLsoN ErAL LIQUID FUEL BURNING APPARATUS Filed Aug.50, 1958 3 Sheets-Sheet 3 /glg 3 Patented Nov. 5, 1940 UNITED STATESPATENT -OFFICE 2,220,858 LIQUID FUEL BURNING APPARATUS ApplicationAugust 30, 1938, :Serial N0. 227,556

22 Claims.

the products of combustion, and facilitating the conversion of furnacesoriginally designed for other fuels, such as coal, to oil burning units.

In the field of liquid fuel combustion involving the use of oil burners,prior burners have proven satisfactory in domestic use when employed inhouses of relatively large size requiring the use of large burners andfurnaces. However, such burners and furnaces are too large for smallhomes. They are not economical for such use and are difilc'ult to holdto the small fuel consumption required to heat a small houseeconomically. In the case of pressure oil burners, for instance, it isdifficult to secure satisfactory operation at rates of less than 1.35gallons per hour which is far in excess of the amount of fuel normallyrequired for a small house. While the present wall flame burners offer awide operating range of from five to fifty pounds of oil per hour, theyare expensive because of their wide range and their capacity at thehigher ranges, and for that reason have not been accepted for the smallhomes as the advantage of the higher ranges is of no value and is lostin a small home installation. As a result of this situation, the use ofoil heat in small homes has been restricted.

In meeting this problem of small home heating, the present invention hasfor its major object the provision of a novel type burner particularlysuitable for small heating plants requiring from ve to ten pounds of oilper hour,

this burner being more economical and of greater I eiliciency over asmaller operating range than the larger burners hitherto available.

A further object of this invention is to provide a novel burner assemblythat provides means for a quick and easy conversion of other types ofheating units, such as coal burning furnaces to oil burning furnaces,the conversion of the assembly requiring only a minium of skill tosecure a resultant structure of maximum efliciency.

A further object of this invention is to provide a burner of the wallflame type including a novel flame rim of one-piece construction that isflexible and readily adaptable to any shape or size of furnace, theflexibility of the rim permitting it to be flexed to fit furnaces of anyshape, such as round, rectangular, or oblong.

This invention also aims to provide a burner of the wall flame typeincluding a novel flame rim assembly having clamping means to facilitateproper positioning of the flame rim in the burner with reference to theburner wall and maintenance of the flame rim in its proper position.

A further object of this invention is to provide a burner of the wallflame type including a flame rim and a novel igniting mechanismcomprising means to accurately position the flame rim with respect tothe electrode of the igniter, and means including a relatively simpleelectrical circuit including the flame rim to insure reliable ignition.

Still a further object of'V this invention is to provide aburner of thewall flame type involving a hearth and a centrally disposed fuel and airdistributor, 'the burner including a flame rimand a novel ignitingmechanism comprising means to with means to determine the height of thehearth.

A further object of this invention is to pro vide a novel type burnerand hearth structure especially adapted for original unit installationsof oil burning units.

Still a further object of this invention is to provide a heating unit ofnovel construction wherein the heat developed by the oil burning unit isutilized to the point of maximum efficiency by the provision of novelheat transfer means.

Further objects of this invention will become apparent as thedescription thereof proceeds with reference to the appended claims andthe accompanying drawings wherein:

Figure 1 is a section taken through the bottom 35 portion of a furnaceillustrating a preferred embodiment of the present invention;

Figure 2 is a plan of a portion of the flame rim of this invention;

Figure 3 is a detail of the rim of Figure 2;

Figure 4 is a vertical section of the flame rim;

Figure 5 is a front elevation of the flame rim;

Figure 6 is a side elevation of a preferred embodiment of the supportingbracket of this inven- 4f tion;

Figure 7 is a plan of the bracket of Figure 6; Figure 8 is a frontelevation of the bracket of Figure 6; 5f Figure 9 is a vertical sectionthrough an igniter embodying the present invention;

Figure 10 is a plan of the igniter of Figure 9;-

Figure 11 is a plan of a lower portion of' a furnace embodying anotherpreferred form of the invention with the rotor unit and a portion of theame rim removed; and` A Figure 12 is a section taken on the line I2-I2of Figure l1.

With reference to the drawings wherein like characters are employed todesignate like parts throughout and with particular reference to Figure1, the assembly therein shown comprises generally a furnace composed inpart of a vertical wall II and a floor I2, it being understood that wallII rises to a suitable height and usually forms part of a water jacket.However, it is to be understood that' the oil burner herein described isas readily applicable tr use in hot air furnaces and other types ofheaters.

Wall I I is preferably provided on its inner surface with a peripherallyextending flange I3 which may also be formed as a series of peripherallyspaced grate lugs. A hearth pan I4 is provided of a size to be containedwithin wall I I, this pandividing the lower portion of the furnace into-a combustion chamber I5 and a lower chamber I6. At its central portion,hearth pan I 4 is apertured at I1l to receive a burner collar I8 of afuel distributing and lifting assembly generally indicated at I9.

Burner collar I8 is supported upon a combination shield and support 2Irepresenting in shape a half of a hollow cylinder, support 2| beingsecured to a base 22 suitably supported on furnace floor I2 by levellingscrews 23. Suitable locking means are provided at 24 for the levellingscrews which are preferably three in number as shown. A removable shield20, shown in Figure' 1 in dot and dash lines, `is preferably provided tocompletely enclose the motor casing with support 2| and insure thepassage of cool air over the motor. Casing'20 may be fastened by studs2I' by engaging slots 20 in support 2I, suitable Wing nuts beingprovided as shown.

The upper portion of burner collar I8 is provided With a horizontalflange or shoulder 25 with nuts 26 Welded thereto. These nuts serve tosupport threaded rods 21 which extend downwardly to engage motorbrackets 28 on motor casing 29, the motor brackets being preferablysecured as by wing nuts 3|. A

. Motor casing 29 comprises a stator unit which is the motor casingproper, and a rotor unit generally indicated at 32 which comprises oildistributor tubes as shown at 33 and a fan 34, the assembly beingmounted upon a shaft 35 extending down into the motor casing. The rotorand motor casing is shown in detail in applicatiOrl Serial No. 219,637led J'ulj7 16, 1938, and

further detailed description in this case is not considered necessary.The motor casing is provided as described in the application aboveidentified with apertures 36 surrounded by an air shutter 31 whichcontrols the air passing to the burner.

Between the upper Vnd of motor casing 29 and the lower surface of flange25 of burner collar I8, a plurality of shims 38 are preferably employedto provide means to adjust the height of motor casing 29 with referenceto burner collar I8. 'I'hus by changing the number of shims 38, theposition of motor casing 29 and correspondingly the position of rotor 32which is supported by the motor casing may be changed relative to theremaining elements of the burner assembly as will be hereinafterdescribed. To insure proper alignment and to facilitate the assembly ofshims 38 and motor casing 29 with burner collar I8,

a plurality of guides 4I, preferably three in num-4 ber, are secured toan upper danse 42 en burner collar I8 to guide the shims and the motorcasing into position. The motor casing is provided with an oil line 43and electrical connections 44 in the manner described in the applicationabove iden- A transformer 45 is provided on base 22 for ignitionpurposes, the positioning of the relatively heavy transformer on thebase for the burner unit being of considerable advantage in that theheavy transformer increases the inertia of the assembly and assists inreducing the vibra-l tion that might be generated by operation of theitinit. This increases the quietness of its operaion.

A hearth 46 of suitable refractory material disposed upon hearth pan I4,this hearth being formed as by molding between wall II and the upper endof burner collar I8. As shown, the

hearth is substantially smooth and horizontal.

Adjacent the outerV periphery of hearth 43, a metal flame rim 41 isprovided to facilitate the combustion of the mixture of fuel and airthat is propelled thereagainst from the distributor assembly by reasonof oil distributor tubes 33 and fan 34.

Referring to Figures 2 to 5, inclusive, the flame rim 41, which is animportant feature of the present invention, ispreferably formed'from asingle strip of sheet metal. preferably steel having from 16 to 18 percent chromium and very little carbon, the thickness pf the material inthe assembly preferably being from 0.020 inch to 0.030 inch. Rim 41 ispreferably formed substantially U-shaped in cross section as shown inFigure 4, the base or bottom wall of the U being formed at 48, a shortleg being provided at 49 and a longer leg provided at 5I, leg 5Ipreferably having a bent-over portion 52 at its upper edge to4 increasethe strength and relative rigidity.

In forming the lrim in a manner to permit it being flexed to t intodifferent shapes of furnaces and to enable the use of the same 'rim infurnaces of either circular or rectangular shape, the bend of the U at48 and the leg 49 are severed or divided at spaced intervals as shown at52 (Figure 2). The adjacent ends of the severed section are then bent tofacilitate the sliding or lapping of the end of one section with the endof the adjoining section when the ring is exed as shown in Figure 2.

In this construction, it is preferred that a lapped portion as shown at53 be bent out on the end of each severed section, this lap in apreferred form of the invention being to the extent of l1 degrees asshown in Figure 2. The shaped overlapping portions 53, however, may bedispensed with, and the severed sections of leg 49 simply overlappedwhen the ring is installed.

The short leg portion of each of the ends of the severed sections of thepreferred embodiment as shown at 54 is preferably bent to an extent of 5degrees.

The preferred embodiment of our invention here shown involves a rimcapable of forming a hearth of 22 inches diameter. It is preferred thatleg 49 be inch high, leg 5I, 11/2 inches high and bottom wall 48 H inchWide. These dimensions are to be understood as merely by way of anexample and are not to be considered as limiting in any particular.

Since the severed portions of the rim occur at frequently and regularlyspaced intervals, as for instance, in the order of one inch, it will beseen that the rim of this invention is highly 2,920,858 flexible andcapable of being iiexed, to any deuniform around the entire periphery ofthe rim.

It is readily seen that rim 41 is of material advantage, particularly inthe conversion. of old coal burning furnaces to oil burning units andthat it is easy -to manufacture and can be adapted to any type furnac'e.

In installing rim 41, it is placed upon hearth 46 while the latter isstill green, that is, insufficiently hard to therein, and is a bracketand 8.

Referring to Figures 6, '1 and 8, bracket 56 comprises a downwardlyextending wing 51 provided with apertures serted into the hearthmaterial as shown in Figure 1 and securely held therein by reason ofapertures 58, which are filled by the hearth material. It will be notedthat edge 58 ofwing 51 is angularly shaped with respect to the remainingportions of the wing for a purpose to be later described.

Bracket 56 is formed with a base portion 6I which is designed as shownin Figure 1 to lie substantially flush with the top surface of thehearth. It will be noted that base portion 6I is formed with a portion62 projecting beyond wing 51. Portion 62 operates as a guide forpositioning bracket 56 with reference to wall II. In inserting thebracket, it is forced into the hearth material and pushed towards wallII until projecting portion 62 contacts 'the wall. The pushing of thebracket against and towards the wall is facilitated by angular surface59 on wing 56 previously described.

Base portion 6I is also formed with an upstanding U-shaped elementcomprising a bend at 63 which is secured to base portion 6| as by spotwelding, a relatively short leg at 64 and a relatively long leg at 65,each leg being preferably formed with a keyhole slot 66. Such a slotforms a weakened portion 66' in each leg to determine the line of bendand forms two independent lugs on each leg to grip the flame rim.

In assembling, flame rim 41 is placed in position in brackets 56 betweenlegs 64 and 65. Since legs 64 and 65 are higher than the respective legsof the U-shaped flame rim, portions of each leg can be bent over asshown in Figure 1 to secure flame rim 41 in position.

In assembling the flame rim with the hearth, the name rim is preferablycut to a length such that when in position, the ends thereof will butttogether, the joint being maintained by the bracket 56, the slottedportion of the legs 64 and 65 thereof which when bent over secure thebutted ends of said flame rim together. It will be noted that any one ofthe brackets such as 56, including that used in connection with theigniter, can be utilized to secure the ends of the flame rim together.

Transformer 45 as shown in Figure 1 is provided with a pair of leads 1Iand 12 leading to suitable connections 13 and 14, respectively, on thebottom of an igniter mechanism 15 in chamber I6.

Igniter 15 shown in detail in Figures 9 and 10 comprises an electrode 16having connection subsequently secured in place by 56 of the type shownin Figures 6, '1

prevent the insertion of articles 58 and designed to be in' theprojecting i 3 18f'at one end, a bent over portion or tip 11 at itsupper end, portion 11 being sov positioned with reference to flame rim41 as to provide the necessary spark therewith .to ignite the fuel. A

heat resistant insulating casing 18 is provided about electrode 16, thecasing being formed to closely embrace and support the electrode atportion 19 and to providea hollow space thereabout at the portion shownat 8|, this type of construction being generally shown in Cole PatentNo. tained in place with reference -to insulator 18 by lugv 82 on theelectrode engaging 'a washer 83 in contact witha boss the insulator, theopposite being secured a's by a nut 18.

end of the electrode 86 above connection The support for the electrodepreferably comprises a base plate 86, as shown in Figure 1, ar-

`ranged to lie substantially flush with hearth pan I4. A collar 88 isattached to plate 86 by securing the angle bracket 81 integral therewiththereto, preferably by spot welding. The collar is split and providedwith a screw and nut assembly at 9| to secure it rigidly to theinsulator 18 after installation.

Collar 88 is further provided with a screw and -nut assembly 88lto-provide vertical adjustment of arms J95 as well as collar 92 andbracket 41, secured thereto with respect to the top level of the hearth46. This is an important feature of our invention inasmuch as in manycases the anges I3 on the wall II are not in the same horizontal piane,and a level hearth of uniform thickness could not be made otherwise, aswithout adjustment it would be practically impossible to position -tip11 of electrode 16 with respect to flame rim 41, which acts as thesecond electrode.

Collar 92 is preferably spot iwelded at 93 to member 94 cooperating withlugs 96 on insulator 16, properly positioned at the electrode 16 withrespect to the flame rim 41. At its bottom member 94 is provided withconnection- 14 to transformer 45. -At its upper end, strip 94 is bent atright angles to form a projecting portion 95 which is of a size toperform the same function as projecting portion 62 on bracket 5,6. Thatis, when the igniter is installed in the hearth, portion 95 is placed incontactwith wall II to insure proper positioning the adjacent portion ofthe In addition to tially flush with upstanding U-shaped member of thesame shape as shown at 63, 64 and 65, on bracket 56 is provided tosecure the adjacent portion of flame rim 41 in; position and to insurethe proper relative positioning of the igniter and the flame wall. vportion 95 which lies substanrim.

By reason of its relatively simple construction, the accuratepositioning of the igniter and the maintenance of that position in thehearth is assured as well as the accurate positioning of the igniterwith respect to flame rim 41. As will be noted, the flame rim togetherwith electrode 11 forms the Ispark gap, the flame rim being grounded tothe transformer through member 94 and connection 14. This provides arelatively simple construction and permits easy assembly because of aminimum of parts. When installed, electrodetip 11 is preferably sopositioned that it points slightly in the same direction as' that inwhich the fuel distributor head 82 rotates.

2,051,130. Electrode 16 is securely main-I 84 on the interior of' of theigniter fromthe surface of the hearth, an(

' Installation` Referring to Figure 1, the rst step in' installation forconverting a furnace or boiler to an oil burning unit is theinstallation of hearth pan I4. If the original furnace be provided witha flange or grate lugs as shown at I3 in Figure 1, such lugs may beemployed for supporting the hearth pan. If such lugs are not provided, alength of pipe or some other equivalent means can be provided as a meansof support. The hearth pan is preferably formed of two pieces of sheetiron with overlapping edges to facilitate placing the pan within theheater and is preferably formed from'twenty-six gauge sheet iron.

After the hearth pan has been cut to the outer dimensions, a slot orhole for ig'niter 15 is cut and hole I1 is cut in the center for burnercollar I8.

Burner shield 20, transformer 45, and motor casing 29 are removed fromburner support I9 and rear leg 23 thereof adjusted so that the flange ofburner collar I8 on which hearth pan I4 is designed to rest will be thesame height as rsupports I3 for the outer edge of the hearth pan.

This insures levelling of the hearth pan when installed.

' To protect the rotor support when the unit is -being assembled, acardboard disc is preferably placed in the top of burnercollar I8 in theopening defined by flange 42. Support I9 with the burner collar attachedis passed through the fire door of the heater base opening and shiftedso that the hearth pan fits over the burner collar. The support is thenlevelledl by means of the two front screws 23. The hearth pan is thenplaced in position on lugs I3 and on the burner collar flange.

Screw 9| of the igniter bracket (Figure 9) is removed and the electrodewith the insulator removed from the bracket. The bracket is thenadjusted by loosening screw 89 and sliding the screw in slot 89a untilthe top end of collar 92 is approximately one and one-half inches aboveplate 86, screw 89 then being tightened. Lead 12 from the transformer tothe connection 14 on the igniter. bracket is then secured in place. Theigniter bracket is then placed in position on the hearth pan and theopening thereof covered with suitable protecting means such as severalthicknesses of paper.,

Hearth pan I4 is sealed to wall Il by furnace cement or any othersuitable composition, the joints around the igniter being also sealed.The igniter bracket is then placed in position and adjusted to the toplevel of the hearth at that point, portion 95 thereof being used as aguide to level. The hearth material is then mixed and placed on thehearth pan to a depth ofapproximately one and one-half inches, the depthbeing determined by the fact that it must be level and flush with thetop edge of the burner collar.

Flame rim 41 is then cut to a length correct for butting the endsthereof together, it being understood that more than one piece of namerim material may be used. The cutting of the flame rim is preferablydone at a joint. Care is also taken to insure that the name rim has notwisted or bent joints so that it will rest evenly when in place.

Brackets 56 are then fastened to the name rim, the brackets being spacedabout eight inches apart, one bracket being employed to bind the buttedends of the name rim. The ame rim is then bent to approximately itsrequired shape,

the heater, and the ends are 'secured together. Brackets 6I are thenpressed into the hearth material so that horizontal base portions 5I areflush with the hearth surface and portions 62 are in contact with wallIl. This insures the proper distance between the flame rim and wall II.In addition to its being secured by brackets 56, the flame rim is alsosecured by the igniter bracket.

To prevent any air-leakage under the flame rim, any gap between bottomwall 48 of the flame rim and the hearth surface is filled with hearthmaterial.

It will be noted that as a result of this installation,'the spacebetween the flame rim and the wall is entirely clear of any hearthmaterial and of any supporting bracket element. This is a particularlyimportant feature in that there is no interference whatsoever with theproper functioning of the flame rim.

As the next step, the hearth material is cut from within the igniterbracket. 'Ihe igniter with its insulator and electrode assembly isplaced in placed therein with bosses 490 at the upper edge of theinsulator down to the top edge of the bracket and lead 1I connected tocontact 13.

`The insulator and the electrode assembly are so l positioned that theelectrode points in the direction of the burner rotation, a spark gap ofthreesixteenths of an inch being preferably provided.

To complete the installation of the burner, it is only necessary toremove the` cardboard that was previously placed in burner collar I8,install the motor casing 29 and transformer 45, and make the connectionsto the transformer. Preferably grills of the type shown in Patent No.2,104,691 to Cole are secured to the outer ring of the llame rim as at Gto secure more efficient combustion. Rotor 32 is then placed in motorcasing 29 and the motor casing connected to the oil feed and the sourceof electrical energy. Motor shield 20 of the type described in thecopending application above identified is then applied to support 2l tocompletely encircle the motorA casing and to insure that the air passingto the burner passes over the motor and maintains the motor at itsproper operating temperature.

Operation With reference to Figure 1, assuming that the motor has beenstarted, oil is admitted through the oil pipe 43 and igniter 11 isenergized, the operation is as follows: Air is sucked into openings 36after passing over the motor casing, and

is then blown by fan blades 34 outwardly in close contact with the uppersurface of the hearth until it strikes the inner ring 49 of the iiamerim. It is then deflected upward over the gutter formed between rings 49and 5I and into grill G.

Simultaneous with the air discharge, oil is thrown from distributortubes 33, taking an upwardly curving direction as indicated by thedotted lines in Figure 1, the oil being discharged in the form ofcomparatively large droplets against wall 5I. By reason of the impact ofthe oil against wall 5I, the drops are mechanically broken up into fineparticles and substantially atomized.

Some of the oil striking against the wall 5| flows downwardly and isignited by the igniter. At this stage a comparatively cold flame burnsin the trough formed between rings 49 and 5I. As combustion proceeds,the heat generated by the burning oil follows the impinging oil whichmixes with the air and burns and produces still a hotter ame.. Thisconcentrated heat heats up flame rim I1 with a consequent vaporizationof more oil. The flame gradually increases in size, a portion stillremaining in the gutter formed between two flame rim walls. Shortlythereafter, the amount of vaporized oil increases to an extent that thename entirely leaves the groove or gutter and rises 'to the region aboveand behind the llame rim. I

After a short time the vapor released increases to a point where theflame entirely leaves the groove in the flame rim and the wall on whichthe oil impinges reaches a temperature4 where all of spark is preferablyShut off. However, it may be left on continuously. When this conditionof combustion is reached, the vapor content in the flame rim groove isso high that combustion is prevented therein, it being confined solelyabove and outwardly of the grills G. With the burner so operating.' itis to be noted that a constant supply of cool air is supplied thereto byreason of support 2| and motor shield 20 which insure drawing of airfrom the bottom'of the lower compartment and its passage over the motorand transformer.

In normal operation of the burner, flange 30 on the fan assemblyoperates to deflect the air disblades 34 downwardly substancharge fromthe tially below the horizontal plane of the fan. 'I'his separates theair for combustion from the stream of oil discharged from the oildistributor tubes or flinger tubes 33 with the result that there is notendency for the oil to ignite until it reaches the impact wall where itis vaporized.

Referring to Figurell, a preferred embodiment of thepresent invention isthere shown in a unit adapted to entirely replace a prior furnace or foran original installation. The arrangement shown in Figure 11 includesgenerally a boiler A composed of heat exchange units or elements and acombustion chamber i Connections to the radiators or like heating unitsare made through pipes |05 shown at the top of the boiler andconnections at the rear of the boiler in conventional manner.

'I'he heating or combustion unit preferably comprises a motor unit |06and a combined fan and distributing unit |01 of the same type as shownin Figure 1, a transformer being providedv at |08 and suitable oilcontrol mechanism at |09, the latter being connected to motor unit |06by a feed line A lead ||2 is supplied for the motor in the motor unit|06.

Referring to Figure 12, wherein the combustion unit is shown in detail,the motor casing |06 is supported from a flange ||3 attached to hearthplate ||4 in the same manner as shown in Figure 1. Hearth plate ||4extends outwardly'to a point where it contacts the under side of aflange ||5 formed on a. furnace support ||6. Support 6 is preferablyshaped in plan as shown in Figure l2., the front portion being formed at||1 to provide a door 8 for ready access to the interior of the unit byremoval of the thumb screw H9, the rear portion of support 6 beingformed with an opening |2| to receive the connections to the transformerand the motor from the controls supply connection |18. The latter arepreferably supported within the base of the furnace by hangers such asis shown in part at |23, the hangers being fastened to support H6.

As viewed in Figure 12, transformer |08 and fuel control |09 arepreferably supported upon a A through angle brackets base I2! and abracket 25 to maintain them clear of the floor. Obviously any other typeof support may be employed as desired, and this invention is not to beconsidered to be limited to the type of support shown. 6 Hearth plate||4 is secured to flange ||5 as by studs |26 having nuts |21 thereon. Aring |28,

` preferably of metal, is secured to the top side at hearth plate ||4`by spot welding, riveting or slmilar means, connection preferably being.made |29 which have inward-I ly inturned projections |3| thereon. In`addition to these projections, small angle members |32 are preferablydisposed about the surface at the top side of hearth plate ||4 withangular projections |33 thereon extending toward the periphery of theunit. These members are preferably spot welded or secured by suitablemeans to the top side of hearth plate ||4. The annular space thendeflnedby flange I| I3 and lring |28 is filled with hearth material ofrefractory character as shown in Figure 12, brackets |32 and |29 withtheir Vprojections serving to reinforce the material and maintain it inits proper position,

When the hearthr material isA placed in the unit, a ame rim 41 of thesame type shown in Figures 1, 2 and 3 is installed with the same typebrackets as shown in Figures 6, 7 and 8, grills G of the same typeas'shown at Figure 1 being also employed.

In the construction shown in Figure 12, brackets 56 perform the samefunction as in the unit shown in Figure 1 and serve to space flame rim41 the -correct distance from the edge of ring |28.

Igniter mechanism of the same type shown in Figure 1 is provided at |34,connections being made therefrom to transformer |08 through lead |35 4asshown in Figure 11.

The invention may be embodied in other specic forms Without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come Within the meaning and range of equivalancy of theclaims are therefore intended to be embraced therein.

, What is claimed and desired to be secured by United States LettersPatent is:

1. A hearth construction for liquid fuel burners of the Wall flame typewherein oil and air for ,combustion are discharged from a centrallylocated head in a combustion chamber comprising a substantially fiat bedof refractory'hearth material extending to the periphery of thecombustion chamber and a. one-piece flexible sheet metallic peripheralame rim on said hearth bed near the periphery thereof, said ame rimcomprising a pair of thinupright walls disposed`in spaced, substantiallyparallel, relationship and joined at their bottom edges by a thirdannular wall, said ame rim being located adjacent the periphery of saidcombustion chamber.

2. In a liquid fuel burner of the wall ame type, acombustion chamberhaving a hearth and a peripheral wall adjacent to which wall combustiontakes place in an annular zone, said f hearth serving to close saidchamber adjacent said wall, and a one-piece flexible sheet metal flameyrim spaced inwardly from said wall and in the path of liquid fuel, saidllame rim comprising chamber with said horizontal annular wall, saidflame rim being located adjacent the periphery of said combustion thirdwall disposed substantially flush with said hearth. l 3. In a liquidfuel burner of the wall flame type, a combustion chamber having a hearthand a peripheral wall adjacent to which wall `combustion takes place inan annular zone, said hearth serving to close said chamber adjacent saidwall, and a one-piece flexible sheet metal rim spaced inwardly from saidwall and in the path of liquid fuel, said rim being butted at its freeends to forma flame rim completely intercepting the path of the liquidfuel, said flame rim comprising a pair of thin upright walls disposed inspaced, parallel relationship and joined by a third annular wall locatedadjacent the hearth, said flame rim being located adjacent the peripheryof said combustion chamber.

4. In a liquid fuel burner of the wall flame type, a combustion chamberhaving a hearth and a peripheral wall adjacent to which wall combustiontakes place in an annular zone, said hearth serving to closey saidchamber adjacent said wall, a sheet metal flame rim spaced inwardlyfromsaid wall and in the path of liquid fuel, said flame rim comprising apair of thin upright walls of different heights disposed in spacedparallel relationship and joined by a bottom wall, and means to supportsaid rim on said hearth comprising a plurality of spaced brackets, eachbracket comprising a leg secured in said hearth and projectingsubstantially at right angles to said flame rim, means to secure saidbracket to said rim, in contact with the bottom wall thereof, and meansto space said rim a predetermined distance from said wall, the lattermeans being positioned to lie flush with the surface of said hearth andprovide an unobstructed space between said rim and said wall.

5. In a liquid fuel burner of the wall flame type, a combustion chamberhaving a hearth and a peripheral wall adjacent to which wall combustiontakes place in an annular zone, said hearth serving toclose said chamberadjacent said wall, a sheet metal rim U-shaped in cross section spacedinwardly from said wall and in the path of liquid fuel, and means tosupport said rim on said hearth in predetermined relation to said wallcomprising a series of spaced brackets, each bracket comprising anelongated base plate positioned to extend from contact with said Walltoward the center of said hearth, a depending leg on said base platesecured in said hearth substantially in a plane leading from the centerof said hearth to said wall,` and a plurality of legs projectingupwardly from said base plate at a predetermined distance from saidwall, said legs being spaced to receive said metal rim, said rim beingadapted to seat upon said base plate with its upright walls locatedclosely adjacent, and in parallelism with, said legs, each of said legshaving its upper end bent around one of the legs of said U to securesaid rim in position.

6. The combination as claimed in claim 5, wherein each of said latterlegs is provided with a downwardly extending key hole slot at its upperend to define a weakened portion on each leg to determine the point ofbending and to form two separate spaced lugs on each leg.

'7. In a liquid fuel burner of the wall flame type, a combustion chamberhaving a hearth and a peripheral wall adjacent to which wall combustiontakes place in an annular zone, said .75 hearth serving to close saidchamber adjacent said wall, and a one-piece flexible sheet metal flamerim spaced inwardly from said wall and in the path-of liquid fuel, saidrim comprising a metallic strip substantially U-shaped in crosssectionand vals along one leg and the bend of the U to permit bending of theremaining leg.

8. In a liquid fuel burner oi' the wall flame type, a combustion chamberhaving a hearth and a peripheral wall adjacent to which wall combustiontakes place in an annular zone, said hearth serving to close saidchamber adjacent said wall, and a one-piece flexible sheet metal iiamerim spaced inwardly from said wall and in the path of liquid fuel, saidrim comprising a metal strip substantially U-shaped in cross-section anddivided transversely at spaced intervals along one leg and the bend ofthe U, the adjacent edges of the divided sections being shaped to permitoverlapping of said sections when the remaining leg of the U is bentwithout setting up distorting forces in the other of said legs.

9. A one-piece flexible metal flame rim for an oil burner of the wallflame type and adapted for use in fire boxes of different shapescomprising a relatively straight sheet of metal, bent to substantiallyform a U in cross section and slitted transversely along one leg and thebend of the U to permit bending of the remaining leg longitudinally.

10. In a liquid fuel burner of the wall flame type, a combustion chamberhaving a hearth and a peripheral wall adjacent to which wall combustiontakes place in an 'annular zone, said hearth serving to close saidchamber adjacent said Wall, a one piece flexible metal flame rim spacedinwardly from said wall comprising a base portion substantially flushwith said hearth, a ring extending upwardly from said base portion andsubstatnially normal thereto, and a second ring extending upwardly fromsaid base portion on the wall side of said rst ring, said second ringbeing of greater height than said first ring, the space between saidsecond ring and said wall, below the level of said first ring, beingclear to prevent any'interference with combustion.

11. In a liquid fuel burner of the character wherein combustion takesplace in a chamber having a substantially vertical wall and a bottomdefined by a substantially horizontal hearth of refractory material, abase plate for said hearth, an electrode supporting member arranged tobe supported on said base plate, and means on said member spaced fromsaid base plate a distance equal to the thickness of said hearth, andprojecting outwardly over said hearth toward the periphery of saidcombustion chamber, and a sheet metal iiame rim supported on said lastnamed means.

12. In a liquid fuel burner of the character wherein combustion takesplace in a chamber having a substantially vertical wall and a bottomdened bya substantially horizontal hearth, a metal flame rim on saidhearth positioned to define an annular space closely adjacent said wall,meansfor igniting fuel in .said chamber, and meanson said ignition meansto position said ignition means With'respect to the surface of saidhearth and said wall, and to support said iiame rim in predeterminedspaced relation to said wall.

13. A unitary hearth assembly, comprising a base plate, a hearth on saidbase plate, a metal flame rim on said hearth, means for igniting fuelcomprising an electrode, a heat resistant insulatdivided transversely atspaced intering shell mounted in said hearth and secured to said baseplate for supporting said electrode, an electrical connection on saidelectrode, electrical conducting means on the exterior of said shell tosupport said flame rim in predetermined relation tosaid electrode andsaid base plate, and a second electrica-l connection to said lattermeans to complete a circuit between said electrode and said flame rim.

14. In a liquid fuel burner of the .wall flame type, a base' support', ahearth plate having a central opening secured to said base support, asubstantially vertical fiange surrounding` said opening, a fueldistributing unit in said central opening, heat exchange means on saidbase support including a substantially vertical wall sur-- rounding saidhearth, a adjacent the periphery ring on said hearth plate, thereof andspaced from said heat exchange means to define an annular space, saidring and fiange defining a second annular space, refractory material insaid second 'annular space, means in said second annular space toreinforce said refractory material, and a metal fiame rim on saidhearth. spaced inwardly from said ring and disposed in. the path of fueldischarged from said fuel distributing unit.

15. The apparatus defined in claim 11, wherein said last-named means ismounted for vertical adjustable movement upon said electrode supportingmember.

16. A combined electrode and flame rim supporting assembly, comprising acollar adapted to be rigidly secured port an electrode, supporting saidmember for adjustable vertical movement on said collar, said memberterminating at its upper end in a substantially horizontally directedportion providing a seat for a metal flame rim.

17. 'I'he apparatus defined in claim 16, wherein said member terminatesat its lower end in an electrical connection.

18. The apparatus defined in claim 16, wherein a second collar isrigidly secured to said member intermediate said first collar and saidhorizontal portion, for supporting the upper portion of said electrode.

19. The apparatus defined inclaim 16, wherein said horizontal portion ofsaid member is directed outwardly a predetermined distance and alsoconstitutes a spacer element adapted to cooperate with the walls of thechamber in which the assembly is to be used to properly position thelatter with respect thereto.

20. A hearth construction for liquid fuel burners of the wall fiametype, wherein oil and air for combustion are discharged from a centrallylocated head in a combustion chamber, comprising a bed of refractoryceramic hearth material extending to the periphery of the combustionchamber; and a metallic peripheral fiame rim structure on said hearthbed near the periphery thereof, comprising an upright inner wall and anupright outer wall extending around the hearth -said inner and outerwalls to a hearth plate and to supan upright member, means in spaced,substantially parallel relationship, being integrally joined at theirlower edges to a bottom wall and-cooperating therewith to define anignition gutter, said bottom wall being disposed in substantially airtight relationship with said hearth and said inner wall being lower thansaid outer wall and operable to deflect the discharged air upwardly intointersectionv with the discharged oil adjacent the top of said outerwall.

21. A hearth construction for liquid` fuel burners of the wall fiametype, wherein oil and air for combustion are discharged from a centrallylocated head in a combustion chamber, comprising a bed of refractoryceramic hearth material extending to the periphery of the combustionchamber; and a `metallic peripheral flame lrim structure on said hearthbed near the periphery thereof of 'U-shape in cross-section, the legs ofthe extending substantially at right angles to the hearth to definespaced, substantially parallel inner and outer walls, the bight of the Udefining a bottom wall cooperating with said inner and outer walls todefine an upwardly facing ignition gutter, said bottom wall beingsubstantially flat and disposed in substantially air tight contact withthe hearth material, each transverse cross-section of said rim structurecomprising integrally joined inner, cuter and bottom wall sections, saidinner Wall being so located, and positioned sufiiciently lower than saidouter wall to defiect the discharged'air upwardly into intersection withthe discharged oil adjacent the top of said outer wall. l

22. A hearth construction for liquid fuel burners of the Wall flametype, wherein oil andair f inner wall and a substantially verticalmetallic outer Wall extending. along said combustion chamber wall inspaced, substantially parallel relationship and cooperating with a thirdmetallic wall to define an ignition gutter, said third wall beingdisposed in substantially air tight contact with said hearth andintegrally joined to the lower edges of said outer and inner walls, saidinner `wall being so located and positioned suiiiciently lower than saidouter wall to deflect the discharged airupwardly into intersection withthe discharged oil adjacent the top of said outer wall; and a grillestructure located adjacent the top of' said outer wall and operable toretard upward movement of combustion gases and form a high temperaturecombustion zone along said combustion chamber wall adjacent the level ofsaid grilles, to thereby radiate heat back to said outer wall andrapidly conduct heat to the integrally connected third and inner walls.

JOHN A. WILSON. NOEL H. SU'I'IERFIELD.

A wall, comprising a substantially vertical metallic`"

